An apparatus for producing injection correction impressions of a jaw including teeth is generally known in the art. The apparatus includes a tray which has a bottom side and side surfaces forming a chamber for containing impression material. The tray including a high-viscosity impression material is introduced into the mouth of the patient, and the patient closes the mouth such that the teeth enter the impression material. In this way, a first impression is produced with the first high-viscosity impression material. After hardening of the impression material, the tray is removed from the mouth of the patient. Next, the hardened impression material is partly removed to produce an injection channel for a correction impression material to be used in a following step. The tray is then reintroduced into the mouth of the patient in the same position, and a low-viscosity correction impression material is injected into the injection channel and into portions within the tray which were not accessible during the first step using the high-viscosity impression material. The known apparatus and method conducted therewith may lead to defective impressions due to saliva, blood, air, turbulences and other anatomic influences such as the tongue, the cheek bands and so forth. Such defects may result in the necessity of having to repeat the production of the impression or to insufficient prosthetic results. Thus, the known method is time consuming, stressful, expensive and takes a lot of work.
An apparatus for producing injection correction impressions of a jaw containing teeth is known from U.S. Pat. No. 6,398,550 B1 corresponding to German Gebrauchsmuster DE 200 10 403 U1 and DE 299 20 226 U1. A similar apparatus is known from German Gebrauchsmuster DE 203 08 413 U1. The know apparatus includes an injection correction impression tray having an interior for containing an impression material. The tray includes a closed bottom side into which an impression material is introduced. Furthermore, a casting channel mould can be inserted into the tray. The casting channel mould is removed after having produced the first impression, and the injection channel resulting therefrom is used for the following production of the correction impression.
Another apparatus for producing an injection correction impression of a jaw including teeth is known from German Gebrauchsmuster DE 201 05 176 U1. The apparatus includes an injection correction impression tray having an interior for containing an impression material. The tray has a bottom opening. The apparatus further includes a bottom plate being designed and arranged to be connected to the tray to close the bottom opening. The bottom plate has a plain bottom side which faces the interior of the tray. After having produced the first impression, the bottom plate is removed from the tray to be capable of manually removing parts of the impression material to produce an injection channel for a correction impression mass to be later introduced through the injection channel.
Other apparatuses for producing impressions of a jaw including teeth are known from German Gebrauchsmuster DE 200 21 854 U1, U.S. Pat. No. 6,394,802 B1 and German Patent Application No. DE 196 08 546 A1.
Other apparatuses in which the injection channels are located at the sidewalls in the interior of the tray are known from German Patent Application Nos. DE 100 20 894 A1 and DE 101 53 245 A1. Injection channels and drainage channels, respectively, are attained by selectively removing parts of the wall of the tray. It is not possible to individually choose variable injection channels and drainage channels.
Another method and apparatus is known from German Patent No. DE 195 26 017 C1. The correction impression material is introduced into the tray by injection nozzles which can be later closed, and the surplus of correction impression material exits the tray through outlet nozzles which can also be closed. The nozzles are located at fixed positions in the wall of the tray.
Another apparatus is known from German Gebrauchsmuster DE 201 04 943 U1. An injection channel for the correction impression material is produced by a placeholder hose which can be later removed from the first impression material. The channel is located in the first impression material inside of the tray. Thus, it is difficult to access the channel and to realize controlled application of the correction impression material.
Another apparatus is known from German Patent Application No. DE 10 2005 042 013 A1 and EP 1 759 659 A1 corresponding to US Patent Application No. US 2007/0054237 A1. The apparatus includes an injection correction impression tray and a bottom plate, the bottom plate including a positive protrusion (i.e. a rib) being arranged at its bottom side facing the interior of the tray. In this way, an injection channel for a correction impression material is formed in a position in which the bottom plate is connected to the injection correction impression tray in a way that the protrusion protrudes into the interior of the injection correction impression tray. The bottom plate is designed as a reversing bottom plate having another side being arranged opposed to the bottom side and being designed to be substantially plain.
Another apparatus is known from German Patent No. DE 43 04 421 C1. The apparatus includes an injection channel being located in the inside of the closed tray which cannot be opened. It is not possible to attain variable flow paths of an impression material.